maybe getting closer. have you tried to charge it ? have you tried a jump start which is different to a bump start. unlikely to bump start from cold in this cold weather, assuming it is a diesel, as the glow plugs won't be able to warm the engine before trying to run it.
a new battery may cure the immediate problem, but it is more important to find out why the current one failed. If it is just old age, then fair enough, the problem is cured. BUT if the alternator is not charging the battery properly, then you will just be chucking good money after bad. Likewise, if something is discharging the battery overnight (i.e. a load on the battery, even with ignition off) then the same thing will happen again.
That is why I asked about doing all the above checks. It may be that the battery was on it's last legs, and this cold snap has finished it off. If so, happy banana, and you're off for the cost of a battery. If not, you'll be wasting your money fitting a new battery.
Good Luck